#include <iostream>
using namespace std;

class A
{
public:
    void print()
    {
        cout<<"hello world"<<endl;
    }
    int m_num;

protected:
    int m_index = 12;
private:
    int m_count = 10;

    

};

class B : public A
{
public:
    int m_num;
    void func()
    {
        print();
    }

};

int main()
{
    A a;
    B b;
    b.func();
    
    

    return 0;
}